The Ivatt R1 0-8-2 Tank Locomotives

Ivatt's
C12 suburban tank engines were successful in that they had
a greater capacity than
Stirling's
G1s and
G2s, which they replaced. However, they
were still limited by the adhesion of the 4-coupled design.
Ivatt solved this in 1903, by ordering a
prototype 0-8-2T tank locomotive. Given the GNR designation of Class L1 (LNER R1), this new locomotive
was essentially a tank version of his
Q1 0-8-0 tender locomotive.

Unfortunately, this prototype was too heavy for the intended Metropolitan City Lines, so it was
quickly rebuilt with a smaller boiler and shorter side tanks. Ten more engines were ordered to this
modified design, and all eleven started working the suburban services out of King's Cross.
Whilst operating these services, these engines demonstrated a very fast acceleration to 30mph but
probably never went much faster than 40mph or so.
Thirty more engines were built in 1905 and 1906. The original engines were not a great success in the
London area, so these new locomotives worked goods trains in the West Riding. In 1907, the original
eleven engines moved to the West Riding to also work goods trains.

There was no need for the smaller boiler after the move from the Metropolitan City Lines, so
between 1909 and 1926, they were rebuilt with the original
Q1-type boilers.
Many of these boilers were taken from
Q1s when they were rebuilt with
superheated boilers.
During the rebuilds, seven R1 locomotives had superheaters fitted but had their
working pressure reduced to 170psi.

During the period of small boilers, the R1s had their cylinders lined to 18in to match the
boilers.

In early 1932, there was a proposal to convert some of the R1s to diesel-engined compressed
air locomotives. Three different designs were considered, but they were essentially the same.
The frames, valves, and wheels would have been kept, but the cylinders would have been lined to 18in.
A 400hp 8-cylinder diesel engine would have been in the middle, and would have powered a 4-cylinder
air compressor. An air reservoir would have been at the back, with the cab located at the front.
Air was taken from the reservoir and heated by the diesel exhaust and an oil-fired steam generator, before
entering the cylinders at about 150psi. This project was dropped due to the Depression and the
projected expense.

The first engine was withdrawn in 1927, and the class survived until 1934.
The boilers from Nos. 3138 and 3148 were kept at Doncaster, and were eventually sold for
scrap in 1966.

Technical Details

The following details are for the saturated boilers. The locomotives with superheated boilers
had slightly smaller heating surfaces, a boiler pressure of 170psi, and a weight of 75 tones 4cwt (full).

Cylinders (x2):

20x26in.

Boiler:

Diameter:

4ft 8in

Length:

14ft 8 5/8in

Pressure:

175 lb/sq.in

Heating Surface:

Total:

1439 sq.ft.

Firebox:

137 sq.ft.

Tubes:

1302 sq.ft.

Wheels:

Coupled:

4ft 8in

Trailing:

3ft 8in

Total Wheelbase:

25ft 2in

Tractive Effort:

27,626 lb

Length:

38ft 7.25in

Weight:

(full)

71t 7cwt

Max. Axle Load:

15t 5cwt

Water Capacity:

1500 gallons

Coal Capacity:

2t 10cwt

Preservation

All of the R1s were withdrawn by 1934. None survived into preservation.

Models

I am not aware of any models of the R1 in any scale.

Acknowledgements

Thank you to Mike Morant Collection for the colour illustration of
R1 No. 116.